Gage for verifying the dimensions of screws and screw-threads.



J. DUBAIL.

GAGE FOB. VERIFYING THE DIMENSIONS OF SCREWS AND SCREW THREADS.

APPLIGATION FILED JUNE 20, 1912.

1,092,827. Patented Apr. 14, 1914.

2 SHEETS-SHEET 1.

Witnesses V Inventor Jules I ubail COLUMBXA PLANOGRAPH CO-AVASHINGTON. D. c.

J. DUBAIL. GAGE FOR VERIPYING THE DIMENSIONS OF SCREWS AND SCREW THREADS.

' APPLICATION FILED JUNEZO, 1912.

1,092,827. Patented Apr. 14, 1914.

g 2 SHEETS-SHEET 2.

HHHHHHHH Wim asses a Inventor TED STATES JULES DUBAIL, 0F DELLE, FRANCE.

To all whom it may concern:

Be it known that I, JULns DUBAIL, a subject of the Republic of France, residing at Delle, France, manager de la Socit Industrielle de Delle, have invented a new and useful Improvement ing the Dimensions Threads, fication.

This invention relates to gages for rapidly and easily verifiying the dimensions of screws and threads of all kinds according to certain definite variations or allowances.

The improved gage consists of a pair of interchangeable plates formed with longitudinal serrations corresponding to the various pitches in use and mounted in a housing or holder. The distance separating the plates for a given diameter of screw is regulated so as to vary the allowance, the plates being held in the desired regulated position in the housing by means of bolts or set screws.

Various forms of construction of the present invention are shown in the accompanying drawings, in which Figure 1 is a front view illustrative of one form of construction, and Fig. 2 is an end view corresponding to Fig. 1. Fig. 3 is a front view of a modified construction, and Fig. 4 is a side view corresponding to Fig. 3. Fig. 5 is a front View of another modification and Fig. 6 is a side view corresponding to Fig. 5. Fig. 7 is a front View of a further modification and Fig. 8 is a side view corresponding to Fig. 7.

Referring to Figs. 1 and 2 the gage comprises two plates at, a, preferably of hardened steel, provided on one of their surfaces with a series of longitudinal serrations shaped and rectified correspondingly to the outer profile of the screw to be verified. The plates at, a fit tightly into a U-shaped housing 6 which is provided at both extremities with bolts 0, c for clamping the plates at, a in their adjusted position. Each of the grooved plates a, a is formed with two guide holes cl, d, through which freely pass two micrometric screws 6, 6; these screws being riveted at their lower ends to the bottom of the housing 7), while their opposite ends are threaded to receive nuts f, 7, formed with a milled shank. In order to regulate the distance between the plates a a, according to the diameters of the of Screws and Screwof which the following is a speci- Specification of Letters Patent.

Application filed June 20, 1912;

in Gages for Verify-.

l the apparatus,

Patented Apr. 14%, 1914. Serial No. 704,788.

screws to be verified, a length of screw, or preferably a male thread gage, is inserted through an opening 9 formed in the housing I). To enable this screw or gage to fit correctly in the serrations of the plates a, a, the latter must be so arranged that a recess in the one plate is opposite to a projection in the other; and to insure this the housing I) should be so constructed that this condition isrealized from one end to the other of the apparatus. The nuts f, f of the micrometric screws 0, e, are graduated at the bottomso as to insure the upp r plate a being placed parallel with the lower plate a. lVhen the plates have been so adjusted with the master screw in position the housing 6 is tightened up by means of the bolts 0; and then the master screw is withdrawn through the opening 9 of the apparatus. The master screw may, however, be retained in the gage and the screws to be verified passed between the extremities of the plates projecting beyond the housing. By suitably turning the micrometric screws, knowing their position with respect to the center of the opening formed between the plates a, a at one end may be reduced as desired and the opening at the opposite end increased. These micrometric screws may be dispensed with and the apparatus regulated directly by means of thread gages or standard screws of the dimensions between which it is desired to verify the screws.

With the apparatus that has just been described it is not necessary to have a separate one for each size of screw thread to be verified, but only to substitute other plates at, a, grooved to correspond with the pitch of the screw to be verified. It has furthermore the great advantage of enabling the verification with the same set of plates of all the diameters of a screw thread admitted in the apparatus.

The gage shown in Figs. 3 and 4 difiers from that shown in Figs. 1 and 2 by the use of a different shaped housing for the plates a, the latter being fastened to the planed surface of an open U-shaped part b to which they are fastened by means of setscrews 0. The set-screws c of the upper plate engage in slots 2' so as to permit of regulating the distance between the two plates. This regulation is efiected by means of micrometric screws e, e, provided with graduated nuts f, f; the ends of the screws resting against the extremities of the upper plates. The gage is provided with a handle 7' so as to facilitate its manipulation.

In the modification shown in Figs. 5 and 6 a fixed apparatus is shown, that is to say, the allowance of which is determined before hand by the plates (1 themselves which are fastened to the housing I) by set-screws c.

The apparatus shown in Figs. 7 and 8 has similar plates a to that of the apparatus shown in Figs. 5 and 6 but are fastened in another manner by screws 0 in a fork-shaped holder 1). The difference between the plates a, that is to say, the allowance between the inlet (plus) and the other extremity (minus), by graduating one of the plates permits of exactly reading the degree of precision of the screw thread being tested, according as the part penetrates more or less into the fork.

What I claim as my invention and desire to secure by Letters Patent, is

1. Allowance gage for screws comprising spaced interchangeable plates, out throughout their whole length into longitudinal serrations having the profile of the screws to be verified, the plates being separated at one of their ends to the maximum allowance of the screw to be verified, while at the other end they are separated to the minimum allowance, the gaging of the screw being effected by engaging it between the ends of the plates and by pushing it 'as far as per 'mitted by the clearance which exists between the two sets of serrations, and means for holding the plates in spaced relation.

2. Allowance gage for screws comprising spaced interchangeable plates, cut through out their whole length into serrations having the profile of the screws to be verified, a support for said plates, the plates being separated at one of their ends to the maximum allowance of the screw to be verified, while at the other end they are separated to the minimum allowance, the gaging of the screw to be verified being effected by engag ing it between the ends of the plates at one end and by pushing it as far as permitted by the clearance which exists between the two sets of teeth.

8. Allowance gage for screws comprising spaced interchangeable plates cut throughout their length into longitudinal serrations having the profile of the screws tobe verified, a casing for said plates, the plates being difierently separated at their ends, and locking screws for fixing the plates in the casing.

In testimony whereof I afix my signature in presence of two witnesses.

, J ULES DUBAILQ Witnesses:

GEO. Grrronn, ARNOLD ZUBER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

